Off-trail snowmobiles must be able to advance through deep snow, whether it be soft powder or heavy damp snow. In either case, an off-trail snowmobile must be able to propel itself onto the snow rather than through the snow. Off-trail snowmobiling is done most of the time at relatively low speeds compared to the maximum speed the snowmobile is capable of, or compared to cruising speeds on groomed trails. Because of this low speed, the snowmobile cannot rely on its own momentum to get through the deep snow but rather on its floatation characteristics to push the snowmobile on top of the snow and reduce the drag between the snow and the snowmobile body components.
Several structural parts of a snowmobile are playing a role in maintaining the snowmobile on top of the snow. A drive track and skis provide the majority of the floatation. In an off-trail snowmobile, the drive track is usually wider and longer than on an on-trail snowmobile so as to provide better floatation. The snowmobile has a frame to which skis are attached through a pair of front suspensions. The front suspensions are connected to the skis at attachment points. The type of suspension can become critical while riding off trails as they can influence the weight balance of the vehicle. Other body parts of a snowmobile are designed for aesthetic purposes, reducing noise to the environment and for reducing drag with ambient air.
However, even by applying the above-mentioned principles, some snowmobiles, while having great trail riding performance, fail in riding through deep snow. When riding in deep snow these snowmobiles push the snow instead of floating on the snow.
Therefore, there is a need for a snowmobile designed for deep snow riding. Such an off-trail snowmobile design would avoid accumulation of the snow at the hull and at the drive track without compromising maneuverability.